1. Field of the Invention
The invention relates to a pixel structure and a manufacturing method thereof, and particularly to a pixel structure having a storage capacitor and a manufacturing method of the pixel structure.
2. Description of Related Art
By virtue of the increasing demands for displays and the rising awareness of environmental protection, a thin film transistor liquid crystal display (TFT-LCD) featuring superior properties including high definition, optimal space utilization, low power consumption, and no radiation has gradually become the mainstream product in the market of the displays. To comply with the users' requirements for high contrast ratio, no gray scale inversion, little color shift, high luminance, full color, high color saturation, fast response speed, stable display frames, and wide viewing angle, the TFT-LCD that satisfies said requirements has been developing.
In general, the TFT-LCD mainly includes two substrates and a liquid crystal layer sandwiched between the two substrates. A pixel array is configured on one of the substrates, and a color filter array is configured on the other. FIG. 1 is a cross-sectional view illustrating a pixel structure of a conventional TFT-LCD. The pixel structure 100 includes a TFT 110, a pixel electrode 120, and a lower electrode 130 of a storage capacitor. The pixel electrode 120 is electrically connected to the TFT 110. The lower electrode 130 of the storage capacitor and the pixel electrode 120 together form the storage capacitor for stabilizing the display frames of the pixel structure 100.
Nonetheless, the conventional lower electrode 130 of the storage capacitor and the gate 112 of the TFT 110 are made of the same metal layer, which results in the reduction of the aperture ratio of the pixel structure 100. When the pixel structure 100 is applied to a transmissive LCD, the light emission efficacy of the backlight source needs to be improved for maintaining the display luminance to some extent, which leads to additional power consumption.